Crayfish are different from many other aquatic species in that they remove oxygen from air or water using specialized gill chambers. As a result, they can survive for six to seven months out of the water if in a humid environment. If kept in captivity, they'll often spend days out of the water if given a platform out of water.

Well they should only live out of water for about a good two to three hours. I recommend you never put them out of water. You are risking them for their oxygen supply. Always have some amount of water that they can swim in or breathe in. Otherwise, it is not good.

My crayfish went "exploring" a couple months ago...found him today (dead) in a moderately traveled part of the house. He was NOT there a few days ago and is in too good of condition for one of my cats to have helped him.